Relationship between surfactant proteins B and C and obstructive sleep apnea: is serum SP-B concentration a potential biomarker of obstructive sleep apnea?
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Surfactant proteins B and C are mainly synthesized, secreted by alveolar type II cells, and affected by hypoxia and mechanical stretches. We hypothesized that their serum levels might be altered by intermittent hypoxia and swing of intrathoracic pressure of obstructive sleep apnea (OSA).
Consecutive 140 middle-aged males, suspicious of OSA determined by polysomnography, were studied. Surfactant proteins B and C were determined by ELISA.
Surfactant protein B (41.39 ± 6.01 vs 44.73 ± 7.62 ng/L, p = 0.005), not C (32.60 ± 6.00 vs 32.43 ± 6.44 ng/L, p = 0.61), significantly lowered in moderate to severe OSA subjects than in non to mild OSA subjects. Severity of OSA is inversely correlated with serum surfactant protein B. Adjusting age, body mass index, and smoking history, compared to subjects with surfactant protein B (SP-B) ≥43.35 ng/L, those with SP-B <43.35 ng/L showed significantly increased 1.528-fold risk for moderate to severe OSA (p = 0.009), whereas no association between surfactant protein C and OSA was observed. Prevalence of moderate to severe OSA in lower SP-B group is higher than that in higher SP-B group (62.7 vs 38.4 %, p = 0.003). Serial and parallel tests on Epworth sleep scale (ESS) and SP-B evaluation can be complementary and prove helpful with high specificity (94.44 %) and sensitivity (84.48 %) to detect moderate to severe OSA.
Serum surfactant protein B, rather than C, is decreased in some individuals with moderate to severe OSA, compared to non to mild OSA subjects. Serum surfactant protein B might be a potential biomarker to diagnose OSA.
KeywordsObstructive sleep apnea Surfactant protein Biomarker
Obstructive sleep apnea
Alveolar type II cells
Body mass index
Fasting blood glucose
Surfactant protein B
Surfactant protein C
Krebs von den Lungen-6
Lowest oxyhemoglobin saturation
Oxygen desaturation index of 3 %
Oxygen desaturation index of 4 %
Epworth sleep scale
Positive predictive value
Negative predictive value
This study was supported by the National Natural Science Foundation of China (grant number: 81260017)
Conflict of interest
The authors declare that they have no conflict of interest.
- 14.Liang S, Li N, Heizhati M, et al. (2015) What do changes in concentrations of serum surfactant proteins A and D in OSA mean? Sleep BreathGoogle Scholar
- 19.Braems GA, Yao LJ, Inchley K et al (2000) Ovine surfactant protein cDNAs: use in studies on fetal lung growth and maturation after prolonged hypoxemia. Am J Physiol Lung Cell Mol Physiol 278:754–764Google Scholar
- 24.Lye M, Wang L, Li E et al (1991) Pulmonary surfactant will secure free airflow through a narrow tube. J Appl Physiol 71:742–748Google Scholar
- 28.Lancaster LH, Mason WR, Parnell JA et al (2008) Obstructive sleep apnea is common in IPF [abstract]. Am J Respir Crit Care Med 177:A247Google Scholar
- 29.Sumita Y, Sugiura T, Kawaguchi Y et al (2010) Genetic polymorphisms in the surfactant proteins in systemic sclerosis in Japanese: T/T genotype at 1580 C/T (Thr131Ile) in the SP-B gene reduces the risk of interstitial lung disease. Pneumonol Alergol Pol 78:224–228Google Scholar